Shiqianaphaenops Tian

Tian, Mingyi, Huang, Sunbin, Wang, Xinhui & Tang, Mingruo, 2016, Contributions to the knowledge of subterranean trechine beetles in southern China's karsts: five new genera (Insecta, Coleoptera, Carabidae, Trechinae), ZooKeys 564, pp. 121-156 : 125-127

Taxon classification Animalia Coleoptera Carabidae

Shiqianaphaenops Tian gen. n.

Type species.

Shenaphaenops majusculus Uéno, 1999 (Cave Feng Dong, Shiqian, Guizhou).

Diagnosis.

Medium-sized aphaenopsian trechine beetles, with sparsely pubescent body, elongated head, reduced frontal furrows, tridentate right mandible, 4-setose mentum, tumid propleura, widened 1st protarsomere and bisetose on each of abdominal ventrites.

Generic characteristics.

Medium-sized aphaenopsian trechines, yet not too highly modified morphologically; eyeless, unpigmented and apterous; body slender and elongate, with slender and long appendages; covered with sparse pubescence, hairs being much longer on head and pronotum than on elytra; head elongate, longer than prothorax, much longer than wide; frontal furrows short, with two pairs of supra-orbital pores; right mandible tridentate; labial suture clear; mentum 4-setose, tooth simple and short, blunt at apex; submentum 9-setose; antennae long, nearly extending to elytral apex; prothorax longer than wide, propleura visible from above; pronotum elongate, longer than wide, widest near front; only anterior pairs of lateromarginal setae; elytra elongate-ovate, strongly convex, shoulders distinct and rounded, lateral margins ciliated throughout; striae faintly impressed; two dorsal and the pre-apical pores present on each elytron; humeral group of marginal umbilicate pores not aggregated; protibia without longitudinal groove externally; 1st protarsomere in both sexes widened and angularly produced externally, with a row of comb-like setae on ventral side; 1st and 2nd protarsomeres modified in male; ventrite VII with two pairs of setae in both sexes.

Remarks.

Uéno (1999) hesitantly treated the two trechine species found in Shiqian County, eastern Guizhou as members of the genus Shenaphaenops Uéno, 1999, which had been set up based on a single female collected in Shuicheng County, northwestern Guizhou. However, he realized some striking differences and the geographical gap between the Shiqian species and the type species Shenaphaenops humeralis Uéno, 1999. Apart from the somewhat similar general body configurations in both Shiqianaphaenops gen. n. (Fig. 1) and Shenaphaenops (Fig. 2), many character states of generic importance are different, such as: (1) 1st protarsomere in both sexes widened apically and distinctly produced externally, covered with a ctenidium structure ventrally in Shiqianaphaenops which, amongst trechines, is only found in this genus; (2) right mandible tridentate in Shiqianaphaenops , versus bidentate in Shenaphaenops ; (3) labial suture clear in Shiqianaphaenops , but completely missing in Shenaphaenops ; (4) ventrite VII in male bisetose in Shiqianaphaenops , versus 4-setose in Shenaphaenops ; (5) in male, both 1st and 2nd protarsomeres modified in Shiqianaphaenops , versus only 1st protarsomere being modified in Shenaphaenops ; (6) pubescence weaker and sparser, hairs much longer on head and pronotum than on elytra in Shiqianaphaenops , versus generally denser and hairs being of same length in Shenaphaenops ; (7) base of pronotum much narrower than front in Shiqianaphaenops , versus only slightly narrower in Shenaphaenops ; (8) elytra broader, with humeral angles rounded in Shiqianaphaenops (Fig. 3A), versus more slender, with humeral angles distinctly angular in Shenaphaenops (Fig. 3B); (9) marginal sides of elytra ciliate throughout, versus smooth in Shenaphaenops ; (10) in Shiqianaphaenops , median lobe of aedeagus stout and thick, broadly rounded dorsally, basal part comparatively small, with an indistinct sagittal aileron, inner sac armed with a very large copulatory piece; apical lobe contracted at apex, roundly blunt in lateral view, but pointed in dorsal view; parameres thin, much shorter than median lobe, each bearing three long setae at apex (Fig. 4A, B). In contrast, median lobe of aedeagus in Shenaphaenops slender and thin, gently expanded dorsally, basal part comparatively large, with a small but distinct sagittal aileron; apical lobe indistinctly contracted at apex, obtuse in lateral view, broad in dorsal view; inner sac armed with a large copulatory piece; parameres shorter than median lobe, left one slightly longer than right one, each bearing two long setae at apex (Fig. 4C, D).

Etymology.

Shiqian+Aphaenops, to indicate that both known members of this genus occur in Shiqian County, eastern Guizhou Province. Gender masculine.

Range.

China (eastern Guizhou) (Fig. 5c).

Known so far by two very similar species from two caves in Shiqian County: Shenxian Dong and Feng Dong. Since Shenxian Dong lies very close to Feng Dong, only about one kilometre in distance across a shallow valley, with still another cave just between them, all three caves may prove belong to a same cave system. Perhaps this is why both Uéno’s species from Shiqian County are not too different from each other. Feng Dong is a large and beautiful cave (Fig. 6A, B). The beetle (Fig. 6C) is sympatric with millipedes, crickets and frogs.

Material examined.

Shenaphaenops humeralis Uéno, 1999: a male, Cave Shendong Migong (Shendong in the original description), Muqiao, Laoyingshan, Shuicheng County, northwestern Guizhou, 26°35'15"N / 104°59'47"E, 1910 m in altitude, VIII-22-2014, Mingyi Tian leg., deposited in the insect collections of South China Agricultural University (SCAU).

Shiqianaphaenops majusculus ( Uéno, 1999), comb. n.: 3 males, V-1-2015, Cave Feng Dong, Tangshan, Shiqian County, 27°29'10"N / 108°15'23"E, 700 m in altitude, Mingyi Tian & Jingli Cheng leg., in SCAU; 6 males & 4 females, ibid., VIII-1-2015, same collectors, in SCAU.

Shiqianaphaenops cursor ( Uéno, 1999), comb. n.: We have not seen any material. We visited Cave Shenxian Dong, the type locality, in August 2015, but failed to catch anything. The cave is badly disturbed by human activities.